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Mangium is a promising timber species. Its sapwood is narrow
and light colored. Its heartwood is medium brown, hard, strong, and durable in
well-ventilated situations, although not in ground contact. The grain is
straight on the tangential face and slightly interlocked on the radial face. A
pleasing fiddlehead pattern sometimes occurs.
Seasoning
The wood seasons fairly rapidly and without developing serious defects. In Sabah it is used for most purposes after 3 months of air drying. Warping, end splitting, and surface checking are negligible. In the early stage of seasoning, however, heartwood areas can collapse, particularly on quartersawn boards.
The timber responds satisfactorily to preservative treatment. It is fairly easily impregnated using standard techniques such as the full-cell pressure method.
Mechanical Properties
Some properties of a single mangium board submitted to the Forest Products Laboratory in Madison, Wisconsin, are given in Table 2. The specific gravity, the modulus of elasticity, and the hardness values are similar to those of black walnut (Juglans nigra), one of the finest cabinet woods of North America. The modulus of rupture and the compression values are somewhat higher than those of walnut.
TABLE 2 Physical Properties of Mangium Wood(a)
|
Property |
Measurement |
|
Specific gravity (weight and volume) |
0.56 |
|
Specific gravity (oven-dry weight/green volume) |
0.50(b) |
|
Modulus of rupture (kilopascals) |
106,000 |
|
Modulus of elasticity (kilojoules) |
11,600 |
|
Compression (parallel) | |
|
Maximum crush (kilopascals) |
60,000 |
|
Modulus of elasticity (kilojoules) |
14,800 |
|
Hardness (newtons) |
4,900 |
(a) The figures are based on a single board at a moisture
content of 11 percent.
(b) Estimated.
Source: J. Winandy, Forest Products
Laboratory, Madison, Wisconsin.
Although the wood sample used in these tests had a specific gravity of 0.56, plantation-grown timber is more commonly between 0.4 and 0.45. Timber from natural stands is normally about 0.6.
The wood planes well and sands easily, producing a lustrous, smooth surface without torn fibers. It also drills satisfactorily, but the base should be supported to prevent unevenness around the edge of the drilled holes. The timber turns well, requiring only low to moderate pressure. Boards can be nailed without splitting, even at their ends.
Uses
Mangium wood makes attractive furniture and cabinets, door frames, window parts, moldings, cabinets, and sliced veneer. It is also employed as a light-duty building timber for uses such as framing and weatherboarding.
Because of its density and calorific value (4,800-4,900 kcal per kg), the wood makes good fuel. Although the tree has not been planted on a large scale for firewood, it appears well suited for this purpose.
Seven- and eight-year-old plantations produce wood that makes excellent particle board. Quality particle board is also produced from a mixture of 30 percent mangium and 70 percent Albizia falcataria.
The fiber length in mangium wood is 1.0-1.2 mm. In tests in Australia, unbleached and bleached pulps have been produced satisfactorily from 9-year-old plantation-grown mangium from Sabah. With the sulfate process, wood chips and wood-plus-bark required only moderate amounts of alkali to yield in excess of 50 percent of screened pulp with excellent papermaking properties. With the neutral sulfite semichemical process, pulp yields were even higher, ranging from 61 to 75 percent.
The pulps were readily bleached to brightness levels acceptable for use in fine papers. They proved comparable to the pulps from commercial eucalypts and are suitable for the manufacture of products such as liner boards, bags, wrapping papers, and multiwall sacks. Because of its density and pulp yield, it was concluded that mangium wood should command higher prices than other fast-growing plantation pulpwoods such as Gmelina arborea, Albizia falcataria, Anthocephalus chinensis, and Eucalyptus deglupta.
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